Cold effect analysis and screening of SNPs associated with cold‐tolerance in the olive flounder Paralichthys olivaceus

Abstract

Olive flounder Paralichthys olivaceus is an important mariculture fish and cold stress limits to its growth and survival during winter. In the present study, the cold‐tolerant (CT) and cold‐sensitive (CS) flounder were defined after cold treatment (0.7 ± 0.05°C). Cold effects on histological and physiological and gene expression levels were analyzed. The correlation analyses between single nucleotide polymorphism locus (SNP) in hsp70, yb‐1 and hmgb1 and the trait of cold tolerance were performed. The results showed that flounder gill was obviously damaged after treatment and more serious lesions in some of the epithelial cell layers were observed in the CS group. ATP concentration and pyruvate kinase activity in the CT group were significantly higher than those in the CS group (p < 0.05). Expression levels of hsp70 and yb‐1 were both up‐regulated markedly after cold treatment (p < 0.05). Nine, twenty‐one and ten SNPs were screened from hsp70, yb‐1 and hmgb1 partial sequences, respectively. Among them, 3 SNPs in hsp70 and 2 SNPs in hmgb1 showed significant difference in the two groups. Allele G of the SNP 8 (locus 1797) in hsp70 was only observed in the CT group. In the SNP 7 (locus 725) of hmgb1, genotype TT and allele T, and genotype CC and allele C were associated with cold tolerance and cold sensitive, respectively. Furthermore, one haplotype (TTG) generated from SNPs of hsp70 gene among CT and CS individuals showed significant relationship with cold tolerance (p = 0.031). Two haplotypes (ATG) and (TCT) generated from SNPs of hmgb1 were significantly associated with resistance (p = 0.001) and sensitive (p = 0.002) in cold treatment, respectively. These SNPs, genotype, alleles and haplotypes of hsp70 and hmgb1 may be related to the cold resistance of flounder, and could be candidate markers potentially for further selective breeding.

Different cold tolerances among three strains of large yellow croaker: related to antioxidant defense and energy metabolism

“…2-3). Cold tolerance in sh was not only related to cold experience (Scott and Johnston 2012), but also was closely correlated with parental inheritance (Nie et al 2019). Fish in NZ group, MY group and DQ group were mainly distributed from the east of the Qiongzhou Strait to the west of the Pearl River Estuar, from the northern part of the South China Sea to the southern part of the East China Sea, from the central part of the East China Sea to the southern part of the Yellow Sea, respectively (Zhang et al 2011).…”

An updated review of cold shock and cold stress in fish

“…Comparing cold‐tolerant and cold‐sensitive olive flounders, the cold‐sensitive individuals tended to have more gill damage (branchial lamellae swelling, epithelial hypertrophy and rupture) following cold stress (15 to 0.7°C, c . 1°C per h) than cold‐tolerant individuals (Nie et al ., 2019a).…”

“…HSP70 expression in cold-shocked rohu (Labeo rohita Hamilton 1822; 26 to 4 C for 3 h) was most elevated in the spleen and liver, and also in the kidney and muscle with respect to a control group (Giri et al, 2014). In 1 C per h), however, strain-dependent differences in single-nucleotide polymorphisms (SNPs) for hsp70 genes were observed, and coldtolerant individuals had higher pyruvate kinase activity and ATP reserves than cold-sensitive fish (Nie et al, 2019a). Cold-induced RNA-binding protein (cirbp) and high-mobility group box 1 (hmgb1) gene transcription were both upregulated in the gills of zebrafish cooled from 28 to 12 C (3 C per h) after 1 day, with cirbp transcription returning to baseline levels whereas hmgb1 remained upregulated after 3 days at 12 C (Chou et al, 2008).…”

Transcriptomic Networks Reveal the Tissue-Specific Cold Shock Responses in Japanese Flounder (Paralichthys olivaceus)

“…In addition, many studies have pointed out that tissues involved in the physiological response and acclimation to low-temperature stress can exhibit tissue-specific characteristics [ 8 , 9 , 10 ]. For example, fish gills are directly exposed to aquatic environment, are the target for the temperature stress response, and are involved in many physiological processes, including respiration, ion- and osmo-regulation, immune response, and the acid–base balance [ 11 ].…”